Earth moving, construction and mining equipment and the like are often used in rough, off-road terrain. These machines often employ an endless drive with track shoes that is better able to propel the machines in such environments over obstacles and uneven terrain, etc. The track chains, which include shoes, are held together by a series of interconnected track links, pins and bushings that are supported on the drive sprocket, idler and support rollers of the machine. As can be imagined, a device is typically provided that allows the track chain to be routed about the drive sprocket, idler and support rollers before the free ends of the chain are joined together. This device is called a “master link”.
Also, depending on the weight of the machine, the size of the chain, the environment in which the machine operates, and other factors, the chains and/or track shoes may wear or be damaged and may require periodic inspection, servicing, repair, and/or replacement. Hence, a master link may also be provided in the chain to allow disassembly of the chain (i.e., separation of two ends of the chain).
As can be imagined, there can be a great deal of tension on the track chain as the master track links are being mated and assembled to the track chain, and even more tension after the track chain and the pair of master track links have been assembled. This may make the pair of master track links prone to be separated over time. If this separation happens in an unplanned manner, the machine and track will need to be serviced, resulting in loss profits.
Also, master track links typically provide a split rail, intended to support the weight of the machine. More specifically, the rail usually comprises the portions of the pair of master track links that are opposite of where the shoe is typically attached. The rail is usually split, meaning that one side of the rail is formed by one master link while the other side of the rail is formed by the other master link. Since the rail is split, both master links need to be hardened, such as by induction heat treatment, in their respective rail portions to be able to withstand the weight exerted on the track links. Manufacturing and heat treating the master track links can be costly.
Furthermore, some master track links are prone to slippage along a direction that is lateral or perpendicular to the direction that the track chain is traveling. This is undesirable as it may eventually lead to one master track link disengaging the other master track link, which could lead to the disassembly of the track chain undesirably at an unplanned time.